Philips TDA1300TT, TDA1300T Datasheet

INTEGRATED CIRCUITS

DATA SHEET

TDA1300T; TDA1300TT

Photodetector amplifiers and laser supplies

Preliminary specification

1997 Jul 15

Supersedes data of 1995 Nov 16

File under Integrated Circuits, IC01

Philips Semiconductors	Preliminary specification

Photodetector amplifiers and laser

TDA1300T; TDA1300TT

supplies

FEATURES

∙Six input buffer amplifiers with low-pass filtering with virtually no offset

∙HF data amplifier with a high or low gain mode

∙Two built-in equalizers for single or double speed mode ensuring high playability in both modes

∙Full automatic laser control including stabilization and

an on/off switch and containing a separate supply VDDL for power reduction

∙Applicable with N-sub laser with N-sub or P-sub monitor diode

∙Adjustable laser bandwidth and laser switch-on current slope

∙Protection circuit preventing laser damage due to supply voltage dip

∙Optimized interconnect between pick-up detector and TDA1301

∙Wide supply voltage range

∙Wide temperature range

∙Low power consumption.

QUICK REFERENCE DATA

GENERAL DESCRIPTION

The TDA1300 is an integrated data amplifier and laser supply for three beam pick-up detectors applied in a wide range of mechanisms for Compact Disc (CD) and read only optical systems. It offers 6 amplifiers which amplify and filter the focus and radial diode signals adequately and provides an equalized RF signal for single or double speed mode which can be switched by means of the speed control pin.

The device can handle astigmatic, single Foucault and double Foucault detectors and is applicable with all N-sub lasers and N-sub or P-sub monitor diode units.

After a single initial adjustment the circuit keeps control over the laser diode current resulting in a constant light output power independent of ageing. The chip is mounted in a small SO24 or TSSOP24 package enabling mounting close to the laser pick-up unit on the sledge.

SYMBOL	PARAMETER		CONDITIONS	MIN.	TYP.	MAX.	UNIT
VDD	supply voltage			3	−	5.5	V
Diode current amplifiers (n = 1 to 6)
Gd(n)	diode current gain			1.43	1.55	1.67
IO(d)	diode offset current			−	−	100	nA
B	3 dB bandwidth		Ii(d) = 1.67 μA	50	−	−	kHz
RFE amplifier (built-in equalizer)
td(eq)	equalization delay		fi = 0.3 MHz	−	320	−	ns
td(f)	flatness delay		double speed	−	5	−	ns
Laser supply
Io(L)	output current		VDDL = 3 V	−	−	−100	mA
ORDERING INFORMATION
TYPE			PACKAGE
NUMBER	NAME		DESCRIPTION			VERSION
TDA1300T	SO24	plastic small outline package; 24 leads; body width 7.5 mm				SOT137-1
TDA1300TT	TSSOP24	plastic thin shrink small outline package; 24 leads; body width 4.4 mm				SOT355-1

1997 Jul 15

2

Philips Semiconductors	Preliminary specification

Photodetector amplifiers and laser

TDA1300T; TDA1300TT

supplies

BLOCK DIAGRAM

I6	23	I6in	6	1.5x	Id6out	2	O6
I5	20	I5in	5	1.5x	Id5out	5	O5
I4	24	I4in	4	1.5x	Id4out	1	O4
I3	22	I3in	3	1.5x	Id3out	3	O3
I2	19	I2in	2	1.5x	Id2out	6	O2
I1	21	I1in	1	1.5x	Id1out	4	O1
				95, 120, 134 or	TDA1300T
				240 kΩ
			Ii(central)	−4
				I/V
HG	11					9
							RFE
	12
LS
						10	RF
ADJ	14	VDD	(N-sub) or	Vgap
		IADJ	(P-sub)
						8	VDDL
MI	17	Vmon	(N-sub) or	OTA	ILO	16	LO
		Imon	(P-sub)
VDD	18					7
			SUPPLY		ON/OFF		LDON
	15
GND
				13
				CL		MBG474

Fig.1 Block diagram.

1997 Jul 15

3

Philips Semiconductors	Preliminary specification

Photodetector amplifiers and laser

TDA1300T; TDA1300TT

supplies

PINNING

	SYMBOL	PIN	DESCRIPTION
	O4	1	current amplifier 4 output
	O6	2	current amplifier 6 output
	O3	3	current amplifier 3 output
	O1	4	current amplifier 1 output
					handbook, halfpage
	O5	5	current amplifier 5 output
	O2	6	current amplifier 2 output
	LDON	7	control pin for switching the laser on
			and off
	VDDL	8	laser supply voltage
	RFE	9	equalized output voltage of sum signal
			of amplifiers 1 to 4
	RF	10	unequalized output
	HG	11	control pin for gain switch
	LS	12	control pin for speed switch
	CL	13	external capacitor
	ADJ	14	P-sub monitor (if connected via
			resistor to GND);
			N-sub monitor (if connected to VDD)
	GND	15	ground (substrate connection)
	LO	16	laser output; current output
	MI	17	monitor diode input (laser)
	VDD	18	supply
	I2	19	photo detector input 2 (central)
	I5	20	photo detector input 5 (satellite)
	I1	21	photo detector input 1 (central)
	I3	22	photo detector input 3 (central)
	I6	23	photo detector input 6 (satellite)
	I4	24	photo detector input 4 (central)

O4	1		24	I4
O6	2		23	I6
O3	3		22	I3
O1	4		21	I1
O5	5		20	I5
O2	6	TDA1300T	19	I2
LDON	7		18	VDD
VDDL	8		17	MI
RFE	9		16	LO
RF	10		15	GND
HG	11		14	ADJ
LS	12		13	CL
		MBG472

Fig.2 Pin configuration.

1997 Jul 15

4

Philips Semiconductors	Preliminary specification

Photodetector amplifiers and laser

TDA1300T; TDA1300TT

supplies

FUNCTIONAL DESCRIPTION

The TDA1300T; TDA1300TT can be divided into two main sections:

∙Laser control circuit section

∙Photo diode signal filter and amplification section.

Laser control circuit section

The main function of the laser control circuit is to control the laser diode current in order to achieve a constant light output power. This is done by monitoring the monitor diode. There is a fixed relation between light output power of the laser and the current of the monitor diode. The circuit can handle P-sub or N-sub monitor diodes.

N-sub MONITOR

In this event pin 14 (ADJ) must be connected to the positive supply voltage VDD to select the N-sub mode. With an adjustable resistor (RADJn) across the diode the monitor current can be adjusted (and so the laser light output power) if one knows that the control circuit keeps the monitor voltage Vmon at a constant level of approximately 150 mV.

P-sub MONITOR

In this event pin 14 (ADJ) is connected via resistor RADJp to ground. The P-sub mode is selected and pin 14 (ADJ)

acts as reference band gap voltage, providing together

with RADJp an adjustable current lADJ. Now the control circuit keeps the monitor current at a level which is 10lADJ.

The circuit is built up in three parts:

∙The first part is the input stage which is able to switch between both modes (N-sub or P-sub).

∙The second part is the integrator part which makes use

of an external capacitor CL. This capacitor has two different functions:

–During switch-on of the laser current, it provides a current slope of typically:

Io(L) 10–6

------------- ----------- (A/s) t CL

– After switch-on it ensures that the bandwidth equals

BP		K × Gext		× 90×10–9
		-------------------------------------------------CL		(Hz)
			× Imon

in case of P-sub monitor or

RADJn × × × –9

BN ----------------K Gext 870 10 (Hz) CL

in case of N-sub monitor, where

Gext represents the AC gain of an extra loop amplifier, if applied, and K = Imon/ IL which is determined by the laser/monitor unit. Imon is the average current (pin 17) at typical light emission power of the laser diode.

∙The third part is the power output stage, its input being the integrator output signal. This stage has a separate

supply voltage (VDDL), thereby offering the possibility of reduced power consumption by supplying this pin with the minimum voltage necessary.

It also has a laser diode protection circuit which comes into action just before the driving output transistor will get saturated due to a large voltage dip on VDDL. Saturation will result in a lower current of the laser diode, which normally is followed immediately by an increment of the voltage of the external capacitor CL. This could cause damage to the laser diode at the end of the dip.

The protection circuit prevents an increment of the capacitor voltage and thus offers full protection to the laser diode under these circumstances.

Photo diode signal filter and amplification section

This section has 6 identical current amplifiers. Amplifiers 1 to 4 are designed to amplify the focus photo diode signals. Each amplifier has two outputs: an

LF output and an internal RF output. Amplifiers 5 and 6 are used for the radial photo diode currents and only have an LF output. All 6 output signals are low-pass filtered with a corner frequency at 69 kHz. The internal RF output signals are summed together and converted to a voltage afterwards by means of a selectable transresistance.

This transresistance RRF can be changed between 140 kΩ (3.3 V application) or 240 kΩ (5 V application) in combination with the P-sub monitor. In the event of the N-sub monitor selection, RRF can be changed between 70 kΩ (3.3 V application) and 120 kΩ (5 V application). The RF signal is available directly at pin 10 but there is also an unfiltered signal available at pin 9.

The used equalization filter has 2 different filter curves:

∙One for single-speed mode

∙One for double-speed mode.

1997 Jul 15

5

Philips Semiconductors	Preliminary specification

Photodetector amplifiers and laser

TDA1300T; TDA1300TT

supplies

Table 1 Gain and monitor modes

	PIN		MONITOR MODE		RRF (kΩ)		INTENDED APPLICATION AREA
HG		ADJ
0		RADJp connected	P-sub		140
		to ground					3.3 V
0		1	N-sub		70
1(1)		RADJp connected	P-sub		240
		to ground					5 V
1(1)		1	N-sub		120
Note
1. Logic 1 or not connected.
Table 2 Speed and laser modes; note 1
						MODE
PIN		DEFAULT
			SPEED					LASER
		VALUE(2)
			SINGLE		DOUBLE		on		off
LS		1	1		0		X(3)		X(3)
LDON		1	X(3)		X(3)		1		0

Notes

1.1 = HIGH voltage (VDD); 0 = LOW voltage (GND); X = don’t care.

2.If not connected.

3.X = don’t care.

LIMITING VALUES

In accordance with the Absolute Maximum Rating System (IEC 134).

SYMBOL	PARAMETER	CONDITIONS	MIN.	MAX.	UNIT
VDD	supply voltage		−	8	V
Pmax	maximum power dissipation		−	300	mW
Tstg	storage temperature		−65	+150	°C
Tamb	operating ambient temperature
	TDA1300T		−40	+85	°C
	TDA1300TT		−40	+70	°C
V (1)	electrostatic handling pin 16	note 2	−2	+2	kV
es
	electrostatic handling (all other pins)		−3	+3	kV

Notes

1.Classification A: human body model; C = 100 pF; R = 1500 Ω; Ves = ±2000 V. Charge device model: C = 200 pF; L = 2.5 μH; R = 0 Ω; Ves = 250 V.

2.Equivalent to discharging a 100 pF capacitor through a 1.5 kΩ series resistor.

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